Revert of base: Remove using:: declaration from version.h header.

chrome/installer/setup/install_worker.cc

Index: chrome/installer/setup/install_worker.cc
diff --git a/chrome/installer/setup/install_worker.cc b/chrome/installer/setup/install_worker.cc
index a1eea40b3e16a7e0884eda6f97c0c7bead35e6c2..4ed8a72c4cf009045a9c7ef6994ccb0a6fce3076 100644
--- a/chrome/installer/setup/install_worker.cc
+++ b/chrome/installer/setup/install_worker.cc
@@ -79,8 +79,8 @@
 // products managed by a given package.
 // |old_version| can be NULL to indicate no Chrome is currently installed.
 void AddRegisterComDllWorkItemsForPackage(const InstallerState& installer_state,
-                                          const base::Version* old_version,
-                                          const base::Version& new_version,
+                                          const Version* old_version,
+                                          const Version& new_version,
                                           WorkItemList* work_item_list) {
   // First collect the list of DLLs to be registered from each product.
   std::vector<base::FilePath> com_dll_list;
@@ -122,7 +122,7 @@
                            const base::FilePath& setup_path,
                            const base::FilePath& archive_path,
                            const base::FilePath& temp_path,
-                           const base::Version& new_version,
+                           const Version& new_version,
                            WorkItemList* install_list) {
   DCHECK(install_list);
   base::FilePath installer_dir(
@@ -225,7 +225,7 @@
 void AddProductSpecificWorkItems(const InstallationState& original_state,
                                  const InstallerState& installer_state,
                                  const base::FilePath& setup_path,
-                                 const base::Version& new_version,
+                                 const Version& new_version,
                                  bool is_new_install,
                                  bool add_language_identifier,
                                  WorkItemList* list) {
@@ -308,8 +308,8 @@
                         const base::FilePath& archive_path,
                         const base::FilePath& src_path,
                         const base::FilePath& temp_path,
-                        const base::Version* current_version,
-                        const base::Version& new_version,
+                        const Version* current_version,
+                        const Version& new_version,
                         WorkItemList* install_list) {
   const base::FilePath& target_path = installer_state.target_path();
 
@@ -503,7 +503,7 @@
 // state key if running under an MSI installer.
 void AddUninstallShortcutWorkItems(const InstallerState& installer_state,
                                    const base::FilePath& setup_path,
-                                   const base::Version& new_version,
+                                   const Version& new_version,
                                    const Product& product,
                                    WorkItemList* install_list) {
   HKEY reg_root = installer_state.root_key();
@@ -650,7 +650,7 @@
 void AddVersionKeyWorkItems(HKEY root,
                             const base::string16& version_key,
                             const base::string16& product_name,
-                            const base::Version& new_version,
+                            const Version& new_version,
                             bool add_language_identifier,
                             WorkItemList* list) {
   list->AddCreateRegKeyWorkItem(root, version_key, KEY_WOW64_32KEY);
@@ -987,8 +987,8 @@
 
 bool AppendPostInstallTasks(const InstallerState& installer_state,
                             const base::FilePath& setup_path,
-                            const base::Version* current_version,
-                            const base::Version& new_version,
+                            const Version* current_version,
+                            const Version& new_version,
                             const base::FilePath& temp_path,
                             WorkItemList* post_install_task_list) {
   DCHECK(post_install_task_list);
@@ -1010,7 +1010,7 @@
 
     // |critical_version| will be valid only if this in-use update includes a
     // version considered critical relative to the version being updated.
-    base::Version critical_version(installer_state.DetermineCriticalVersion(
+    Version critical_version(installer_state.DetermineCriticalVersion(
         current_version, new_version));
     base::FilePath installer_path(
         installer_state.GetInstallerDirectory(new_version).Append(
@@ -1138,8 +1138,8 @@
                          const base::FilePath& archive_path,
                          const base::FilePath& src_path,
                          const base::FilePath& temp_path,
-                         const base::Version* current_version,
-                         const base::Version& new_version,
+                         const Version* current_version,
+                         const Version& new_version,
                          WorkItemList* install_list) {
   DCHECK(install_list);
 
@@ -1283,7 +1283,7 @@
 
 void AddDelegateExecuteWorkItems(const InstallerState& installer_state,
                                  const base::FilePath& target_path,
-                                 const base::Version& new_version,
+                                 const Version& new_version,
                                  const Product& product,
                                  WorkItemList* list) {
   base::string16 handler_class_uuid;
@@ -1354,7 +1354,7 @@
 }
 
 void AddActiveSetupWorkItems(const InstallerState& installer_state,
-                             const base::Version& new_version,
+                             const Version& new_version,
                              const Product& product,
                              WorkItemList* list) {
   DCHECK(installer_state.operation() != InstallerState::UNINSTALL);
@@ -1468,7 +1468,7 @@
 
 void AddOsUpgradeWorkItems(const InstallerState& installer_state,
                            const base::FilePath& setup_path,
-                           const base::Version& new_version,
+                           const Version& new_version,
                            const Product& product,
                            WorkItemList* install_list) {
   const HKEY root_key = installer_state.root_key();